In the past, flame retardancy in polymers has generally been achieved though one of two methods.
Flame retardancy can be achieved through the use of a halogenated monomer. Lee, U.S. Pat. No. 4,108,943, July 5, 1977, discloses such a composition. The use of a halogenated monomer is often unsatisfactory in practice because it requires, as a first step, the halogenation of the monomer. This separate step is costly and inconvenient.
Flame retardancy can be achieved through the use of various halogenated additives. Lee, U.S. Pat. No. 4,108,943, July 5, 1977, discloses such a composition. The use of halogenated additives to achieve flame retardancy is undesirable in at least one aspect. Addition of an amount of halogenated additive sufficient to achieve the desired amount of flame retardancy will often have a very deleterious effect on the physical properties of the resultant polymer. For example, addition of a halogenated additive will often lower the thermal stability of the polymer leading to increased polymer degradation on exposure to heat.
It is desirable to produce a flame resistant polymer without deleteriously affecting the physical properties of the resultant polymer. It is to this goal that the present invention is directed.